Narrative:

After leaving a holding pattern at nottingham VOR while descending through approximately 2300 ft and while navigating through an area of precipitation and thunderstorms, both air conditioning packs failed. A descent to a lower altitude was continued as we worked on the pressurization problem. We were assigned 11000 ft. As we leveled, ATC asked our altitude because he saw us at approximately 10500 ft. We replied 11000 ft but then noticed that 2 of our altimeters were still set at 29.92 with pressure at 29.42. We reset and climbed back to 11000 ft. No further mention was made of the incident. Our workload was obviously heavy but we should not have missed this basic procedure. Someone always must pay attention to flying.

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Original NASA ASRS Text

Title: ACR ON ARR HAS BOTH AIR CONDITIONING PACKS FAIL. NEGLECT TO RESET ALTIMETER PASSING FL180.

Narrative: AFTER LEAVING A HOLDING PATTERN AT NOTTINGHAM VOR WHILE DSNDING THROUGH APPROX 2300 FT AND WHILE NAVIGATING THROUGH AN AREA OF PRECIPITATION AND TSTMS, BOTH AIR CONDITIONING PACKS FAILED. A DSCNT TO A LOWER ALT WAS CONTINUED AS WE WORKED ON THE PRESSURIZATION PROB. WE WERE ASSIGNED 11000 FT. AS WE LEVELED, ATC ASKED OUR ALT BECAUSE HE SAW US AT APPROX 10500 FT. WE REPLIED 11000 FT BUT THEN NOTICED THAT 2 OF OUR ALTIMETERS WERE STILL SET AT 29.92 WITH PRESSURE AT 29.42. WE RESET AND CLBED BACK TO 11000 FT. NO FURTHER MENTION WAS MADE OF THE INCIDENT. OUR WORKLOAD WAS OBVIOUSLY HVY BUT WE SHOULD NOT HAVE MISSED THIS BASIC PROC. SOMEONE ALWAYS MUST PAY ATTN TO FLYING.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.